Don't delete code whose purpose you haven't understood. A condition that looks pointless was written by someone for a reason; find the reason first, then decide. git log -S"strange_condition" before deleting is the minimum procedure — a countermeasure to refactoring enthusiasm, not a ban on removal.
The source is G. K. Chesterton, The Thing (1929), the essay “The Drift from Domesticity”. A reformer finds a fence across a road and says he sees no use for it; the wiser reformer answers: if you don't see the use, I certainly won't let you clear it away — go and find out, and when you can tell me why it was put up, I may let you take it down. The argument is about reform in general, not software, and it is asymmetric on purpose: the burden of proof sits with the person removing, because the person who built the fence knew something the passer-by does not.
A backend example. An ingestion job skips rows where updated_at < created_at; the check looks like noise. git log -S"updated_at < created_at" finds the commit, the commit links an incident: an upstream system replayed a month of rows with a broken clock, and the check stopped them from overwriting newer data. The fence now has an owner and a reason. The decision is still open: if that upstream system was retired, the check can go — together with a commit message that says so, so the next reader does not repeat the search. The cheap tools are pickaxe search (git log -S / -G), git blame with -w -M -C to see through moves, the linked issue, and a query of production logs or metrics for how often the branch actually fires.
Where it stops. The fence is not a veto. When the history is gone and nobody can say why, the honest move is to make the removal observable and reversible: log or count the branch first, remove it behind a flag or in a small commit, and watch. Treating every unexplained line as sacred produces the opposite failure — the code nobody dares to touch, which grows by accretion (45). The principle trades against YAGNI (42): YAGNI says don't add what is not needed; the fence says don't assume something is unneeded just because you can't see the need. Its counterpart for generated code is 61.